1. Field of the Invention
The invention relates to an iron type golf club head and, specifically, to an iron type golf club head, the sole portion of which includes a backward bulging section having recesses respectively formed in the upper and lower surfaces thereof.
2. Description of the Related Art
An iron type golf club includes: an iron club mainly used for shots from the fairway, rough, bunker etc., and for tee shots in a short hole (a par-three hole); and, a utility club containing a head having a similar shape to the iron head.
As the head of the iron club, there is widely used a head in which its face portion to its hosel portion are made of stainless steel, carbon steel, various alloys or the like.
The iron club head includes a face surface for hitting a ball and a sole surface facing the ground. The head has a hosel portion on the heel side thereof. A shaft is inserted into the hosel portion and is fixed thereto by fixing means such as adhesive.
In the case of an iron type golf club head including a bulging section of a shape formed by bulging backward the sole side portion thereof, its center of gravity is low and the distance (gravity depth) of the center of gravity from the face surface is large. The iron type golf club head including such bulging section tends to be liked by a powerless player.
JP-A-H08-10359 discloses an iron type golf club head in which recesses are formed in both of the upper and lower surfaces of such sole bulging section to thereby adjust the balance and weight of the head.
US-A1-2012-0196703 discloses an iron head which includes grooves (channels) formed along the front edge portion of the sole thereof. According to US-A1-2012-0196703, formation of such grooves can enhance the repulsion characteristics of the head when hitting a ball.
Besides, U.S. Pat. No. 5,749,795B2, U.S. Pat. No. 7,980,960B2, U.S. Pat. No. 5,472,203B2, US-A1-2012-0289361, As the patent document involved with a golf club head, US-A1-2012-0202615 and JP-UM-U-3115147 are also related to the iron type golf club head.
In JP-A-H08-10359, since the lower surface side recess of the sole bulging section is disposed below the upper surface side recess thereof, the upper surface side and lower surface side recesses are both small in depth, whereby the degree of freedom for adjusting the weight and balance of the head is small.